CN113809247A - Zinc oxide film, preparation method thereof and quantum dot light-emitting diode - Google Patents

Zinc oxide film, preparation method thereof and quantum dot light-emitting diode Download PDF

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CN113809247A
CN113809247A CN202010544099.7A CN202010544099A CN113809247A CN 113809247 A CN113809247 A CN 113809247A CN 202010544099 A CN202010544099 A CN 202010544099A CN 113809247 A CN113809247 A CN 113809247A
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zinc oxide
film
quantum dot
group
dot light
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CN113809247B (en
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郭煜林
吴龙佳
张天朔
李俊杰
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TCL Technology Group Co Ltd
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/115—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers comprising active inorganic nanostructures, e.g. luminescent quantum dots
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/14—Carrier transporting layers
    • H10K50/16—Electron transporting layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K2102/00—Constructional details relating to the organic devices covered by this subclass

Abstract

The invention relates to the technical field of display, and provides a zinc oxide film which comprises a zinc oxide base film and Lewis alkali combined with zinc oxide in the zinc oxide base film. According to the zinc oxide film provided by the application, after Lewis alkali is introduced to the surface of the zinc oxide-based film, the zinc oxide surface defects and unsaturated Zn2+The zinc oxide film is used as a Lewis acid center to capture electrons of Lewis alkali, can reduce the defects of the grain boundary of zinc oxide particles and the surface of the film, and reduces the capture of the defects to the electrons, thereby improving the electron transmission performance.

Description

Zinc oxide film, preparation method thereof and quantum dot light-emitting diode
Technical Field
The invention belongs to the technical field of display, and particularly relates to a zinc oxide film and a preparation method thereof, and a quantum dot light-emitting diode.
Background
In the conventional inorganic electroluminescent device, electrons and holes are injected from a cathode and an anode, respectively, and then are recombined in a light emitting layer to form excitons for light emission. Quantum Dots (QDs) have a variety of characteristics, including: (1) the emission spectrum can be adjusted by changing the particle size; (3) the excitation spectrum is wide, the emission spectrum is narrow, and the absorptivity is strong; (3) the light stability is good; (4) longer fluorescence lifetime, etc. The semiconductor quantum dot material has important commercial application value as a novel inorganic semiconductor fluorescent material. Conduction band electrons in wide bandgap semiconductors can be accelerated under high electric fields to obtain high enough energy to strike QDs to cause it to emit light. Due to its excellent Light Emitting characteristics, Quantum dots are rapidly developing in the application of Quantum Dot Light Emitting Diodes (QLEDs).
ZnO is an n-type semiconductor material with a direct band gap, has a wide forbidden band of 3.37eV and a low work function of 3.7eV, and has the advantages of good stability, high transparency, safety, no toxicity and the like, so that ZnO can be used as a proper electron transport layer material. ZnO has many potential advantages, its exciton confinement energy is as high as 60meV, far higher than other wide bandgap semiconductor materials (GaN is 25meV), and ZnO exciton confinement energy (60meV) is 2.3 times of its room temperature heat energy (26meV), so ZnO exciton can exist stably at room temperature.
ZnO exists as a thin film in the fabrication of QLED devices, while polycrystalline thin films are often accompanied by defective formation in spin-on or spray-on processes. Defects of the electron transport layer film can weaken the transport of carriers and reduce the recombination efficiency of electrons and holes in the light emitting layer.
Disclosure of Invention
The invention aims to provide a zinc oxide film, a preparation method thereof and a quantum dot light-emitting diode, and aims to solve the problems that surface defects are generated and the transmission of current carriers is weakened when ZnO is formed into a film.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present application provides a zinc oxide thin film comprising a zinc oxide-based film, and a Lewis base combined with zinc oxide in the zinc oxide-based film.
In a second aspect, the present application provides a method for preparing a zinc oxide thin film, comprising the steps of:
preparing alcoholic solution of Lewis base;
and depositing the alcoholic solution of the Lewis alkali on a zinc oxide base film, and heating to prepare the zinc oxide film.
In a third aspect, the present application provides a quantum dot light emitting diode, comprising an anode and a cathode oppositely arranged, a quantum dot light emitting layer arranged between the anode and the cathode, and an electron transport layer arranged between the cathode and the quantum dot light emitting layer; the electron transmission layer is a zinc oxide film, the zinc oxide film comprises a zinc oxide base film and Lewis alkali combined with zinc oxide in the zinc oxide base film.
According to the zinc oxide film provided by the first aspect of the application, after Lewis alkali is introduced to the surface of the zinc oxide-based film, the zinc oxide surface defects and unsaturated Zn2+The zinc oxide film is used as a Lewis acid center to capture electrons of Lewis alkali, can reduce the defects of the grain boundary of zinc oxide particles and the surface of the film, and reduces the capture of the defects to the electrons, thereby improving the electron transmission performance. When the zinc oxide film is used as the electron transport layer of the quantum dot light-emitting diode, the interface performance of the zinc oxide film is improved, the film forming quality of the zinc oxide film is improved, and the electron transport capability is enhanced, so that the electron-hole recombination efficiency can be improved, and the stability of a device can be enhanced.
According to the preparation method of the zinc oxide film provided by the second aspect of the application, the zinc oxide film can be prepared only by depositing the alcoholic solution of the Lewis base on the zinc oxide base film and then heating. The method is simple to operate and easy to realize. More importantly, after Lewis alkali is introduced to the surface of the zinc oxide-based film of the zinc oxide film prepared by the method, the surface defects and unsaturated Zn of the zinc oxide are generated under the heating condition2+The zinc oxide film is used as a Lewis acid center to capture electrons of Lewis alkali, can reduce the defects of the grain boundary of zinc oxide particles and the surface of the film, and reduces the capture of the defects to the electrons, thereby improving the electron transmission performance.
In the quantum dot light-emitting diode provided by the third aspect of the present application, the electron transport layer is a zinc oxide film, and the zinc oxide film includes a zinc oxide-based film, and a Lewis base combined with zinc oxide in the zinc oxide-based film. Compared with a zinc oxide base film, the electron transmission capability of the zinc oxide film modified by Lewis alkali is increased, the electron-hole recombination efficiency is improved, the device stability is enhanced, and the photoelectric performance of the quantum dot light-emitting diode can be effectively improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
Fig. 1 is a flow chart of a process for preparing a zinc oxide thin film according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a quantum dot light emitting diode provided in an embodiment of the present application.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
In this application, the term "and/or" describes an association relationship of associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a is present alone, A and B are present simultaneously, and B is present alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.
In the present application, "at least one" means one or more, "a plurality" means two or more. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, "at least one (a), b, or c", or "at least one (a), b, and c", may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, and c may be single or plural, respectively.
It should be understood that, in various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, some or all of the steps may be executed in parallel or executed sequentially, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
The terms "first" and "second" are used for descriptive purposes only and are used for distinguishing purposes such as substances, interfaces, messages, requests and terminals from one another and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. For example, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX, without departing from the scope of embodiments of the present application. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.
In the description of the present application, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings, which is for convenience and simplicity of description, and does not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus, is not to be considered as limiting.
The weight of the related components mentioned in the description of the embodiments of the present application may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the content of the related components is scaled up or down within the scope disclosed in the description of the embodiments of the present application as long as it is scaled up or down according to the description of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application may be a mass unit known in the chemical industry field such as μ g, mg, g, kg, etc.
In a first aspect, embodiments of the present application provide a zinc oxide thin film, including a zinc oxide-based film, and a Lewis base combined with zinc oxide in the zinc oxide-based film.
According to the zinc oxide film provided by the first aspect of the embodiment of the application, after Lewis alkali is introduced to the surface of the zinc oxide-based film, the surface defects and unsaturated Zn of the zinc oxide are generated2+The zinc oxide film is used as a Lewis acid center to capture electrons of Lewis alkali, can reduce the defects of the grain boundary of zinc oxide particles and the surface of the film, and reduces the capture of the defects to the electrons, thereby improving the electron transmission performance. When the zinc oxide film is used as the electron transport layer of the quantum dot light-emitting diode, the interface performance of the zinc oxide film is improved, the film forming quality of the zinc oxide film is improved, and the electron transport capability is enhanced, so that the electron-hole recombination efficiency can be improved, and the stability of a device can be enhanced.
In some embodiments, the Lewis base comprises at least one aromatic or heteroaromatic ring and an electron withdrawing group bonded to the aromatic or heteroaromatic ring. The ring structure of the aromatic ring or the aromatic heterocyclic ring has strong pi-pi stacking performance, and the electron-withdrawing group and the ring structure of the aromatic ring or the aromatic heterocyclic ring with pi-pi stacking form a conjugated hybrid, so that the electron accepting capacity of the conjugated hybrid is improved, and the electron mobility of the material is enhanced when the conjugated hybrid is used as an electron transport layer, thereby improving the conductivity of the zinc oxide film, accelerating the electron transport and increasing the electron injection. When the zinc oxide film is used as an electron transport layer of a quantum dot light-emitting diode, the recombination efficiency of electrons and holes in a light-emitting layer can be effectively improved.
In some embodiments, the aromatic or heteroaromatic ring is a pi-pi stacked cyclic structure including, but not limited to, a benzene ring, a naphthalene, a pyrrole ring, a pyridine ring. By adopting pi conjugated Lewis base and Lewis acid coordination of zinc oxide surface defects, the crystal boundary of zinc oxide particles and the surface defects of the film can be reduced, and the capture of electrons by the defects is reduced, thereby improving the electron transmission performance. When the zinc oxide film is used as the electron transport layer of the quantum dot light-emitting diode, the interface performance of the zinc oxide film is improved, the film forming quality of the zinc oxide film is improved, and the electron transport capability is enhanced, so that the electron-hole recombination efficiency can be improved, and the stability of a device can be enhanced.
In some embodiments, the electron withdrawing group is selected from at least one of cyano, methoxy, styryl, sulfonic acid, carboxyl, and formyl. The electron-withdrawing group can form a conjugated hybrid with an aromatic ring or an aromatic heterocycle, so that the electron accepting capacity of the zinc oxide is improved, and the electron transmission performance of the modified zinc oxide base film is improved.
In some embodiments, the Lewis base is selected from at least one of 1, 2-dicyanobenzene, methoxybenzene, 2-cyanopyridine, 4-cyanopyridine, cyanoacetophenone, tetracyanobenzene, 1, 4-dimethoxybenzene, and p-methoxyaniline. The zinc oxide film obtained by adopting the Lewis alkali has effectively improved electron transmission capability, improves the electron-hole recombination efficiency when being used as an electron transmission layer of a quantum dot light-emitting diode, and enhances the stability of a device.
As shown in fig. 1, the zinc oxide thin film provided by the first aspect of the embodiments of the present application can be prepared by the following method.
The second aspect of the embodiments of the present application provides a method for preparing a zinc oxide thin film, including the following steps:
s01, preparing an alcoholic solution of Lewis base;
s02, depositing an alcoholic solution of Lewis alkali on a zinc oxide base film, and heating to prepare the zinc oxide film.
In the method for preparing the zinc oxide thin film provided in the second aspect of the embodiment of the present application, the zinc oxide thin film can be prepared only by depositing an alcoholic solution of Lewis base on the zinc oxide base film and then performing heat treatment. The method is simple to operate and easy to realize. More importantly, after Lewis alkali is introduced to the surface of the zinc oxide-based film of the zinc oxide film prepared by the method, the surface defects and unsaturated Zn of the zinc oxide are generated under the heating condition2+The zinc oxide film is used as a Lewis acid center to capture electrons of Lewis alkali, can reduce the defects of the grain boundary of zinc oxide particles and the surface of the film, and reduces the capture of the defects to the electrons, thereby improving the electron transmission performance.
Specifically, in step S01, a Lewis base is dissolved in an alcohol to prepare an alcoholic solution of the Lewis base. The preferred case of Lewis base is as described above, and detailed analysis is not repeated. In some embodiments, the Lewis base comprises at least one aromatic or heteroaromatic ring and an electron withdrawing group bonded to the aromatic or heteroaromatic ring. In some embodiments, the electron withdrawing group is selected from at least one of cyano, methoxy, styryl, sulfonic acid, carboxyl, and formyl. In some embodiments, the Lewis base is selected from at least one of 1, 2-dicyanobenzene, methoxybenzene, 2-cyanopyridine, 4-cyanopyridine, cyanoacetophenone, tetracyanobenzene, 1, 4-dimethoxybenzene, and p-methoxyaniline.
In some embodiments, the alcoholic solution of a Lewis base is selected from alcohols having a carbon number less than or equal to 5. At this time, the alcohol solvent can be effectively melted with Lewis base to form a mixed solution, has a low boiling point, and can be removed in the heating treatment of the following steps, so that the solvent residue is prevented from hindering the electron transport performance of the zinc oxide film.
In some embodiments, the concentration of the Lewis base in the alcoholic solution of the Lewis base is 0.5-2 mol/L, and the proper concentration can enable most defects in the zinc oxide-based film to be combined with the non-coordinated Zn2+The isoacidic centers are combined, thereby improving the electron transport performance of the zinc oxide. If the concentration of the Lewis base is too low, below 0.5mol/L, the Lewis base in the alcoholic solution cannot react with the majority of the defects and the uncoordinated Zn2+The combination of the acidic centers is poor, so that the effect of improving the electron transmission performance of the zinc oxide is good; if the concentration of the Lewis base is too large and is higher than 2mol/L, the Lewis base in the alcoholic solution is excessive, an inert layer can be formed on the surface of the zinc oxide-based film, and the effect of improving the electron transmission performance is not good.
In the above step S02, a zinc oxide-based film is provided. In the present embodiment, the zinc oxide-based film refers to a thin film formed of zinc oxide particles. The zinc oxide-based film can be prepared by a conventional method.
In some embodiments, the zinc oxide-based film is prepared by: mixing zinc salt and an alkali source, and preparing a ZnO particle solution by a sol-gel method; and forming the ZnO particle solution into a film by a solution processing method to prepare the zinc oxide base film. In some embodiments, the zinc oxide in the zinc oxide-based film is zinc oxide nanoparticles.
The zinc salt is selected from inorganic zinc salt and/or organic zinc salt capable of generating zinc ion by ionization, and specifically, at least one of zinc acetate, zinc nitrate, zinc chloride, zinc sulfate and zinc acetate dihydrate can be selected, but not limited thereto. The alkali source is selected from inorganic alkali and/or organic alkali which generates hydroxide ions in a mixed solution formed after the organic solution of the zinc salt is added into the alkali liquor, and includes but is not limited to at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide and tetramethyl ammonium hydroxide.
In some embodiments, the zinc salt is first dissolved in an organic solvent and then mixed with a source of alkalinity. Among them, the organic solvent is preferably an organic alcohol, including but not limited to at least one of organic solvents such as isopropyl alcohol, ethanol, propanol, butanol, pentanol, hexanol, etc. In order to promote the dissolution of the zinc salt, a heating and stirring manner can be adopted. In some embodiments, dissolution is by stirring at 60 ℃ to 80 ℃.
In some embodiments, the zinc salt solution is mixed with the alkali source before the alkali source is dissolved in the organic solvent, and the organic solvent is preferably an organic alcohol, including but not limited to at least one of isopropanol, ethanol, propanol, butanol, pentanol, hexanol, and the like. In a preferred embodiment, the organic solvent in which the alkali source is dissolved is the same as the organic solvent in which the zinc salt is dissolved. And when the zinc salt solution is mixed with the alkali source, the zinc salt solution and the alkali source are mixed and react to generate the zinc oxide nano-particles. Wherein the mixing treatment adopts a stirring and mixing mode, and the stirring time is 1-4 hours.
Deposition of an alcoholic solution of a Lewis base on a zinc oxide-based film can be accomplished using conventional solution processing methods including, but not limited to, spin coating, doctor blading, and ink jet printing.
Depositing alcoholic solution of Lewis base on the zinc oxide base film, and heating to make the Lewis base and the defects in the zinc oxide base film and the uncoordinated Zn2+When the acid centers are combined, the solvent is volatilized at the same time, and a compact film is formed. In some embodiments, the temperature of the heating treatment is 80 ℃ to 120 ℃ for 30 minutes to 60 minutes.
A third aspect of the embodiments of the present application provides a quantum dot light emitting diode, including an anode and a cathode that are oppositely disposed, a quantum dot light emitting layer disposed between the anode and the cathode, and an electron transport layer disposed between the cathode and the quantum dot light emitting layer; the electron transmission layer is a zinc oxide film, and the zinc oxide film comprises a zinc oxide base film and Lewis alkali combined with zinc oxide in the zinc oxide base film.
As shown in fig. 2, in the quantum dot light emitting diode provided in the third aspect of the embodiments of the present application, the electron transport layer is a zinc oxide thin film, and the zinc oxide thin film includes a zinc oxide-based film, and a Lewis base combined with zinc oxide in the zinc oxide-based film. Compared with a zinc oxide base film, the electron transmission capability of the zinc oxide film modified by Lewis alkali is increased, the electron-hole recombination efficiency is improved, the device stability is enhanced, and the photoelectric performance of the quantum dot light-emitting diode can be effectively improved.
In the embodiments of the present application, the zinc oxide film as the electron transport layer is as described above, and is not described herein again for the sake of brevity. In some embodiments, the Lewis base comprises at least one aromatic or heteroaromatic ring and an electron withdrawing group bonded to the aromatic or heteroaromatic ring. In some embodiments, the electron withdrawing group is selected from at least one of cyano, methoxy, styryl, sulfonic acid, carboxyl, and formyl. In some embodiments, the Lewis base is selected from at least one of 1, 2-dicyanobenzene, methoxybenzene, 2-cyanopyridine, 4-cyanopyridine, cyanoacetophenone, tetracyanobenzene, 1, 4-dimethoxybenzene, and p-methoxyaniline.
In some embodiments, the quantum dot light emitting diode further comprises: a hole transport layer disposed between the quantum dot light emitting layer and the anode; in some embodiments, the quantum dot light emitting diode further comprises: a hole injection layer disposed between the anode and the hole transport layer; in some embodiments, the quantum dot light emitting diode further comprises: an electron injection layer disposed between the cathode and the electron transport layer; in some embodiments, the quantum dot light emitting diode further comprises: the hole injection layer is arranged between the anode and the hole transport layer; and an electron injection layer disposed between the cathode and the electron transport layer.
In the embodiment of the application, the quantum dot light emitting diode may further include a substrate, and the anode or the cathode is disposed on the substrate. In some embodiments, the substrate may include a rigid substrate such as glass, metal foil, etc., commonly used rigid substrates, or a flexible substrate such as Polyimide (PI), Polycarbonate (PC), Polystyrene (PS), Polyethylene (PE), polyvinyl chloride (PV), polyvinyl pyrrolidone (PVP), polyethylene terephthalate (PET), etc., which primarily serves as a support.
The quantum dot light-emitting diode in the embodiment of the application is divided into a positive type structure quantum dot light-emitting diode and an inversion type structure quantum dot light-emitting diode.
In one embodiment, a positive type structure quantum dot light emitting diode includes an anode and a cathode disposed opposite to each other, a quantum dot light emitting layer disposed between the anode and the cathode, and an electron transport layer disposed between the cathode and the quantum dot light emitting layer, and the anode is disposed on a substrate. Furthermore, an electron injection layer, a hole blocking layer and other electronic function layers can be arranged between the cathode and the quantum dot light-emitting layer; and a hole functional layer such as a hole transport layer, a hole injection layer and an electron blocking layer can be arranged between the anode and the quantum dot light-emitting layer. In some embodiments of the positive-type quantum dot light emitting diode, the quantum dot light emitting diode comprises a substrate, an anode disposed on a surface of the substrate, a hole transport layer disposed on a surface of the anode, a quantum dot light emitting layer disposed on a surface of the hole transport layer, an electron transport layer disposed on a surface of the quantum dot light emitting layer, and a cathode disposed on a surface of the electron transport layer.
In one embodiment, an inverted structure quantum dot light emitting diode includes an anode and a cathode disposed opposite each other, a quantum dot light emitting layer disposed between the anode and the cathode, and an electron transport layer disposed between the cathode and the quantum dot light emitting layer, with the cathode disposed on a substrate. Furthermore, an electron injection layer, a hole blocking layer and other electronic function layers can be arranged between the cathode and the electron transmission layer; and a hole functional layer such as a hole transport layer, a hole injection layer and an electron blocking layer can be arranged between the anode and the quantum dot light-emitting layer. In some embodiments of the quantum dot light emitting diode with the inverse structure, the quantum dot light emitting diode comprises a substrate, a cathode arranged on the surface of the substrate, an electron transport layer arranged on the surface of the cathode, a quantum dot light emitting layer arranged on the surface of the electron transport layer, a hole transport layer arranged on the surface of the quantum dot light emitting layer, and an anode arranged on the surface of the hole transport layer.
In the embodiment of the present application, the anode may be made of a common anode material and thickness, and the embodiment of the present application is not limited. For example, the anode material may be Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO) conductive glass, or indium tin oxide, indium zinc oxide electrode, or may be other metal materials such as gold, silver, aluminum, and the like.
In the embodiments of the present application, the cathode may be made of a common cathode material and thickness, and the embodiments of the present application are not limited. In some embodiments, the material of the cathode is selected from one or more of a conductive carbon material, a conductive metal oxide material, and a metallic material. Wherein the conductive carbon material includes, but is not limited to, one or more of doped or undoped carbon nanotubes, doped or undoped graphene oxide, C60, graphite, carbon fibers, and porous carbon; the conductive metal oxide material includes, but is not limited to, one or more of ITO, FTO, ATO, and AZO; the metal material includes, but is not limited to, Al, Ag, Cu, Mo, Au, or an alloy thereof. The metal material has a form including, but not limited to, one or more of a dense thin film, a nanowire, a nanosphere, a nanorod, a nanocone, and a hollow nanosphere. In which, materials such as nano-Ag wires or Cu wires are used, which have smaller resistance to enable carriers to be injected more smoothly. The thickness of the cathode is 15-30 nm.
The quantum dots of the quantum dot light-emitting layer can be made of conventional quantum dot materials according to conventional quantum dot types. For example, the quantum dots of the quantum dot light-emitting layer can be one of red quantum dots, green quantum dots, blue quantum dots and yellow quantum dots; the quantum dot material may or may not contain cadmium; the quantum dots can be oil-soluble quantum dots comprising binary phase, ternary phase and quaternary phase quantum dots. In some embodiments, the quantum dot material may be selected from semiconductor nanocrystals of CdS, CdSe, CdTe, ZnSe, ZnTe, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InSb, AlAs, AlP, CuInS, CuInSe, AgS, PbS, PbSe, and core-shell structure quantum dots or alloy structures formed from the above materialsAt least one of quantum dots; in some embodiments, the quantum dot material may be selected from ZnXCd1-XS、CuXIn1-XS、ZnXCd1-XSe、ZnXSe1-XS、ZnXCd1-XTe、PbSeXS1-XAnd at least one of a core-shell structure quantum dot or an alloy structure quantum dot formed by the material. In some embodiments, the quantum dot material may be selected from ZnXCd1-XS/ZnSe、CuXIn1-XS/ZnS、ZnXCd1-XSe/ZnS、CuInSeS、ZnXCd1-XTe/ZnS、PbSeXS1-XThe nano-crystalline material comprises/ZnS semiconductor nano-crystalline and at least one of core-shell structure quantum dots or alloy structure quantum dots formed by the material. The quantum dot light-emitting layer of the material has the characteristics of wide and continuous excitation spectrum distribution, high emission spectrum stability and the like. The thickness of the quantum dot light-emitting layer is 20 nm-60 nm.
The material of the hole injection layer may be made of a hole injection material that is conventional in the art, and may be PEODT: PSS, CuPc, HATCN, WoOx、MoOx、CrOx、NiO、CuO、VOx、CuS、MoS2、MoSe2、WS2、WSe2But is not limited thereto. The thickness of the hole injection layer is 30nm-100 nm.
When the material of the hole transport layer can be a conventional hole transport material, including, but not limited to, high molecular weight polymers such as TFB, PVK, Poly-TPD, TCTA, PEDOT: PSS, F8, etc.; inorganic metal oxides such as copper oxide, nickel oxide, tungsten trioxide, molybdenum trioxide, and the like, or mixtures thereof in any combination, may also be other high performance hole transport materials. The thickness of the hole transport layer is 30nm-100 nm.
The materials of the electron transport layer are as described above and will not be described in detail here. The thickness of the electron transport layer is 60nm-100 nm.
The quantum dot light-emitting diode provided by the third aspect of the embodiment of the application can be prepared by the following method.
In some embodiments, a method of making a quantum dot light emitting diode comprises the steps of:
s01, providing a substrate;
in this step, in one implementation case, the substrate is a composite substrate, including an anode substrate, and a quantum dot light emitting layer bonded at least to the anode substrate. In some embodiments, a hole function layer is further included between the anode and the quantum dot light emitting layer, wherein the hole function layer includes at least one of a hole transport layer and a hole injection layer. In one embodiment, the substrate is a cathode substrate.
In both cases of implementation, the anode substrate or the cathode substrate is pretreated in order to obtain a high-quality thin film when the functional layer is prepared on the anode substrate or the cathode substrate. The basic specific processing steps include: and sequentially carrying out ultrasonic cleaning on the anode substrate or the cathode substrate in deionized water, acetone, absolute ethyl alcohol and deionized water respectively to remove impurities existing on the surface, drying and then cleaning by using an ultraviolet cleaning machine.
S02, preparing an electronic transmission layer on a substrate;
in the step, according to the method, a zinc oxide base film is firstly prepared on a substrate, then Lewis alkali is deposited on the zinc oxide base film, and the electron transport layer is prepared by heating treatment.
Further, when the substrate includes an anode and a quantum dot light emitting layer, a cathode is prepared on the electron transport layer; when the substrate is a cathode substrate, the quantum dot light-emitting layer and the cathode are sequentially prepared on the electron transport layer.
Further, the preparation method also comprises the following steps: and packaging the obtained QLED device. The packaging process can be carried out by a common machine or manually. Preferably, the oxygen content and the water content are both lower than 0.1ppm in the packaging treatment environment, so as to ensure the stability of the QLED device.
The following description will be given with reference to specific examples.
Example 1
A preparation method of a zinc oxide film comprises the following steps:
proper amount of balanceAdding the zinc chloride into 50ml of methanol to form a zinc chloride solution with the total concentration of 0.5 mol/L; stirring at 60 deg.C to dissolve, adding 30ml sodium hydroxide methanol alkaline solution (molar ratio, OH)-：Zn2+1.5). Stirring was continued at 60 ℃ for 1h to give a clear and transparent solution. And then, after the solution is cooled, acetone is used for separating out, ZnO nanoparticles (10-100 nm) are prepared, and a proper amount of ethanol is used for dispersing, so that a ZnO solution is obtained.
And spin-coating the ZnO solution to form a film, spin-coating a 1.2-dicyanobenzene alcohol solution with the concentration of 0.5mol/L on the surface of the ZnO film, and drying at 120 ℃ for 30min to prepare the zinc oxide film.
Example 2
A preparation method of a zinc oxide film comprises the following steps:
weighing a proper amount of zinc nitrate hexahydrate, and adding the proper amount of zinc nitrate hexahydrate into 50ml of methanol to form a zinc nitrate hexahydrate solution with the total concentration of 0.5 mol/L; stirring at 60 deg.C for dissolution, adding 30ml of potassium hydroxide methanol alkaline solution (molar ratio, OH)-：Zn2+1.5). Stirring was continued at 60 ℃ for 1h to give a clear and transparent solution. And then, after the solution is cooled, acetone is used for separating out, ZnO nanoparticles (10-100 nm) are prepared, and a proper amount of ethanol is used for dispersing, so that a ZnO solution is obtained.
And spin-coating the ZnO solution to form a film, spin-coating a methoxyphenylethanol solution with the concentration of 1mol/L on the surface of the ZnO film, and drying at 100 ℃ for 50min to prepare the zinc oxide film.
Example 3
A preparation method of a zinc oxide film comprises the following steps:
weighing a proper amount of zinc acetate dihydrate, and adding the zinc acetate dihydrate into 50ml of methanol to form a zinc acetate dihydrate solution with the total concentration of 0.5 mol/L; stirring at 60 deg.C for dissolving, adding 30ml ethanol alkali solution (molar ratio, OH) of tetrahydroxy ammonium hydroxide pentahydrate-：Zn2+1.5). Stirring was continued at 60 ℃ for 1h to give a clear and transparent solution. And then, after the solution is cooled, acetone is used for separating out, ZnO nanoparticles (10-100 nm) are prepared, and a proper amount of ethanol is used for dispersing, so that a ZnO solution is obtained.
And spin-coating the ZnO solution to form a film, spin-coating a 2-cyanopyridine ethanol solution with the concentration of 2mol/L on the surface of the ZnO film, and drying at the temperature of 80 ℃ for 60min to prepare the zinc oxide film.
Example 4
A quantum dot light-emitting diode comprises a laminated structure of an anode and a cathode which are oppositely arranged, a quantum dot light-emitting layer arranged between the anode and the cathode, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the anode is arranged on a substrate. The substrate is made of a glass sheet, the anode is made of an ITO (indium tin oxide) substrate, the hole transport layer is made of TFB (thin film transistor), the electron transport layer is the zinc oxide film provided in the embodiment 1, and the cathode is made of Al.
Example 5
A quantum dot light-emitting diode comprises a laminated structure of an anode and a cathode which are oppositely arranged, a quantum dot light-emitting layer arranged between the anode and the cathode, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the anode is arranged on a substrate. The substrate is made of a glass sheet, the anode is made of an ITO (indium tin oxide) substrate, the hole transport layer is made of TFB (thin film transistor), the electron transport layer is the zinc oxide film provided in the embodiment 2, and the cathode is made of Al.
Example 6
A quantum dot light-emitting diode comprises a laminated structure of an anode and a cathode which are oppositely arranged, a quantum dot light-emitting layer arranged between the anode and the cathode, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the anode is arranged on a substrate. The substrate is made of a glass sheet, the anode is made of an ITO (indium tin oxide) substrate, the hole transport layer is made of TFB (thin film transistor), the electron transport layer is the zinc oxide film provided in the embodiment 2, and the cathode is made of Al.
Comparative example 1
A quantum dot light-emitting diode comprises a laminated structure of an anode and a cathode which are oppositely arranged, a quantum dot light-emitting layer arranged between the anode and the cathode, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the anode is arranged on a substrate. The substrate is made of a glass sheet, the anode is made of an ITO (indium tin oxide) substrate, the hole transport layer is made of TFB (thin film transistor), the electron transport layer is made of commercial ZnO (from sigma company), and the cathode is made of Al.
Comparative example 2
A quantum dot light-emitting diode comprises a laminated structure of an anode and a cathode which are oppositely arranged, a quantum dot light-emitting layer arranged between the anode and the cathode, an electron transport layer arranged between the cathode and the quantum dot light-emitting layer, and a hole transport layer arranged between the anode and the quantum dot light-emitting layer, wherein the anode is arranged on a substrate. The substrate is made of glass sheets, the anode is made of an ITO (indium tin oxide) substrate, the hole transport layer is made of TFB (thin film transistor), the electron transport layer is made of a ZnO nano material without Lewis alkali modification, and the cathode is made of Al.
The quantum dot light emitting diodes of examples 4 to 6 and the quantum dot light emitting diodes of comparative examples 1 to 2 were subjected to performance tests, and the test indexes and the test methods were as follows:
turn-on voltage and External Quantum Efficiency (EQE): the measurement is directly obtained by adopting an EQE optical test instrument (external quantum efficiency test is used for testing the external quantum efficiency of the QLED device). The test results are shown in table 1 below:
TABLE 1
Figure BDA0002540082070000141
Figure BDA0002540082070000151
As can be seen from table 1, compared with comparative example 1 and comparative example 2, the quantum dot light emitting diode provided in the embodiment of the present application has a reduced turn-on voltage and an improved external quantum efficiency, and it is seen that the performance of the zinc oxide film can be optimized by using Lewis acid-base complex reaction on the surface of zinc oxide, thereby improving the photoelectric performance of the quantum dot light emitting diode.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (13)

1. A zinc oxide thin film comprising a zinc oxide-based film and a Lewis base bonded to zinc oxide in the zinc oxide-based film.
2. The zinc oxide thin film of claim 1, wherein the Lewis base comprises at least one aromatic or heteroaromatic ring and an electron withdrawing group bonded to the aromatic or heteroaromatic ring.
3. The zinc oxide thin film according to claim 2, wherein the electron-withdrawing group is at least one selected from the group consisting of a cyano group, a methoxy group, a styryl group, a sulfonic acid group, a carboxyl group and a formyl group.
4. The zinc oxide thin film of any one of claims 1 to 3, wherein the Lewis base is selected from at least one of 1, 2-dicyanobenzene, methoxybenzene, 2-cyanopyridine, 4-cyanopyridine, cyanoacetophenone, tetracyanobenzene, 1, 4-dimethoxybenzene, and p-methoxyaniline.
5. The preparation method of the zinc oxide film is characterized by comprising the following steps:
preparing alcoholic solution of Lewis base;
and depositing the alcoholic solution of the Lewis alkali on a zinc oxide base film, and heating to prepare the zinc oxide film.
6. The method of claim 5, wherein the Lewis base comprises at least one aromatic ring or aromatic heterocyclic ring and an electron-withdrawing group bonded to the aromatic ring or aromatic heterocyclic ring.
7. The method of claim 6, wherein the electron-withdrawing group is at least one selected from the group consisting of a cyano group, a methoxy group, a styryl group, a sulfonic acid group, a carboxyl group, and a formyl group.
8. The method of claim 5, wherein the Lewis base is at least one selected from the group consisting of 1, 2-dicyanobenzene, methoxybenzene, 2-cyanopyridine, 4-cyanopyridine, cyanoacetophenone, tetracyanobenzene, 1, 4-dimethoxybenzene, and p-anisidine.
9. The method for preparing a zinc oxide thin film according to any one of claims 5 to 8, wherein the concentration of the Lewis base in the alcoholic solution of the Lewis base is 0.5 to 2 mol/L; or the like, or, alternatively,
in the alcoholic solution of the Lewis base, the alcoholic solvent is selected from alcohols with the carbon atom number less than or equal to 5; or the like, or, alternatively,
the temperature of the heating treatment is 80-120 ℃, and the time is 30-60 minutes.
10. The quantum dot light-emitting diode is characterized by comprising an anode and a cathode which are oppositely arranged, a quantum dot light-emitting layer arranged between the anode and the cathode, and an electron transmission layer arranged between the cathode and the quantum dot light-emitting layer; the electron transmission layer is a zinc oxide film, the zinc oxide film comprises a zinc oxide base film and Lewis alkali combined with zinc oxide in the zinc oxide base film.
11. The quantum dot light-emitting diode of claim 10, wherein the Lewis base comprises at least one aromatic or heteroaromatic ring and an electron-withdrawing group bonded to the aromatic or heteroaromatic ring.
12. The qd-led of claim 11, wherein the electron-withdrawing group is selected from at least one of cyano, methoxy, styryl, sulfonic acid, carboxyl and formyl.
13. The qd-led of any one of claims 10 to 12, wherein the Lewis base is selected from at least one of 1, 2-dicyanobenzene, methoxybenzene, 2-cyanopyridine, 4-cyanopyridine, cyanoacetophenone, tetracyanobenzene, 1, 4-dimethoxybenzene and p-methoxyaniline.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115582113A (en) * 2022-09-23 2023-01-10 南昌大学 General synthesis method for in-situ construction of indium oxide modified zinc oxide-zinc sulfide heterostructure photocatalytic water splitting hydrogen production material

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080286907A1 (en) * 2007-05-16 2008-11-20 Xerox Corporation Semiconductor layer for thin film transistors
US20120208313A1 (en) * 2009-07-31 2012-08-16 University Of Washington Methods of forming aggregate particles of nanomaterials
JP2015070000A (en) * 2013-09-26 2015-04-13 株式会社日本触媒 Composition for organic electroluminescent element containing polyallylamine polymer, and organic electroluminescent element using the same
CN104681737A (en) * 2013-11-29 2015-06-03 海洋王照明科技股份有限公司 Organic light emission diode and preparation method thereof
CN105765753A (en) * 2013-11-05 2016-07-13 艾尼股份公司 Inverted polymer solar cells and process for producing the same
CN108795154A (en) * 2017-04-28 2018-11-13 Tcl集团股份有限公司 Zinc oxide base nano particle ink
CN109935718A (en) * 2017-12-15 2019-06-25 Tcl集团股份有限公司 White light quanta point light emitting diode and preparation method thereof
CN110144139A (en) * 2019-04-15 2019-08-20 纳晶科技股份有限公司 A kind of zinc oxide base nano particle ink and photoelectric device

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080286907A1 (en) * 2007-05-16 2008-11-20 Xerox Corporation Semiconductor layer for thin film transistors
US20120208313A1 (en) * 2009-07-31 2012-08-16 University Of Washington Methods of forming aggregate particles of nanomaterials
JP2015070000A (en) * 2013-09-26 2015-04-13 株式会社日本触媒 Composition for organic electroluminescent element containing polyallylamine polymer, and organic electroluminescent element using the same
CN105765753A (en) * 2013-11-05 2016-07-13 艾尼股份公司 Inverted polymer solar cells and process for producing the same
CN104681737A (en) * 2013-11-29 2015-06-03 海洋王照明科技股份有限公司 Organic light emission diode and preparation method thereof
CN108795154A (en) * 2017-04-28 2018-11-13 Tcl集团股份有限公司 Zinc oxide base nano particle ink
CN109935718A (en) * 2017-12-15 2019-06-25 Tcl集团股份有限公司 White light quanta point light emitting diode and preparation method thereof
CN110144139A (en) * 2019-04-15 2019-08-20 纳晶科技股份有限公司 A kind of zinc oxide base nano particle ink and photoelectric device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115582113A (en) * 2022-09-23 2023-01-10 南昌大学 General synthesis method for in-situ construction of indium oxide modified zinc oxide-zinc sulfide heterostructure photocatalytic water splitting hydrogen production material
CN115582113B (en) * 2022-09-23 2023-08-29 南昌大学 General synthesis method for in-situ construction of indium oxide modified zinc oxide-zinc sulfide heterostructure photocatalytic water splitting hydrogen production material

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